package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IVoucherService;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.BeanUtils;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
@Slf4j
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private IVoucherService voucherService;

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private RedissonClient redissonClient;

    public static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }


    private static final ExecutorService seckill_order_executors = Executors.newSingleThreadExecutor();

    @PostConstruct //当前类初始化完成后执行
    private void init(){
        seckill_order_executors.submit(new VoucherOrderHandler());
    }

    private class VoucherOrderHandler implements Runnable {
        @Override
        public void run() {
            while (true){
                try {
                    //1.获取消息队列中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS streams.order >(">"代表最近一条消息)
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create("stream.orders", ReadOffset.lastConsumed())
                    );
                    //2.判断消息获取是否成功
                    if (list == null || list.isEmpty()){
                        //2.1、如果获取失败，没有消息，继续下一次循环
                        continue;
                    }
                    //解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                    //2.2 如果获取成功，可以下单
                    //3.创建订单
                    handleVoucherOrder(voucherOrder);
                    //4.ACK确认 SACK stream.orders g1 id
                    stringRedisTemplate.opsForStream().acknowledge("stream.orders","g1",record.getId());

                } catch (Exception e) {
                    log.error("处理订单异常",e);
                    handlePendingList();
                }
            }
        }

        /**
         * 抛出异常后去pendingList中获取消息再次处理
         */
        private void handlePendingList() {
            while (true){
                try {
                    //1.获取pendingList中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1  STREAMS streams.order 0
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create("stream.orders", ReadOffset.from("0"))
                    );
                    //2.判断消息获取是否成功
                    if (list == null || list.isEmpty()){
                        //2.1、如果获取失败，说明pendingList没有消息，结束循环
                        break;
                    }
                    //解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                    //2.2 如果获取成功，可以下单
                    //3.创建订单
                    handleVoucherOrder(voucherOrder);
                    //4.ACK确认 SACK stream.orders g1 id
                    stringRedisTemplate.opsForStream().acknowledge("stream.orders","g1",record.getId());

                } catch (Exception e) {
                    log.error("处理订单异常",e);
                    try {
                        Thread.sleep(20);
                    } catch (InterruptedException ex) {
                        ex.printStackTrace();
                    }
                }
            }
        }
    }

    //private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);
    //private class VoucherOrderHandler implements Runnable {
    //    @Override
    //    public void run() {
    //        while (true){
    //            try {
    //                //1.获取队列中的订单信息
    //                VoucherOrder take = orderTasks.take();
    //                //2.创建订单
    //                handleVoucherOrder(take);
    //            } catch (Exception e) {
    //                log.error("处理订单异常",e);
    //            }
    //        }
    //    }
    //}

    private IVoucherOrderService proxy;

    /**
     * 修改秒杀代码 根据redis发送消息进行下单
     * @param voucherId
     * @return
     * @throws InterruptedException
     */
    @Override
    public Result seckillVoucher(Long voucherId) throws InterruptedException {
        //获取用户
        Long userId = UserHolder.getUser().getId();
        //获取订单id
        long orderId = redisIdWorker.nextId("order");
        //1.执行lua脚本
        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT, Collections.emptyList(), voucherId.toString(), userId.toString(),String.valueOf(orderId));
        //2.判断结果是否为0
        int r = result.intValue();
        if (r != 0){
            //2.1不为0 ，没有购买资格
            return Result.fail(r == 1 ? "库存不足":"不能重复下单");
        }
        //获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        return Result.ok(orderId);
    }


    //@Override
    //public Result seckillVoucher(Long voucherId) throws InterruptedException {
    //    //获取用户
    //    Long userId = UserHolder.getUser().getId();
    //    //1.执行lua脚本
    //    Long result = stringRedisTemplate.execute(SECKILL_SCRIPT, Collections.emptyList(), voucherId.toString(), userId.toString());
    //    //2.判断结果是否为0
    //    int r = result.intValue();
    //    if (r != 0){
    //        //2.1不为0 ，没有购买资格
    //        return Result.fail(r == 1 ? "库存不足":"不能重复下单");
    //    }
    //    //2.2为0 有购买资格，吧下单信息保存到阻塞队列
    //    VoucherOrder voucherOrder = new VoucherOrder();
    //    //TODO 保存阻塞队列
    //    //2.3返回订单id
    //    long orderId = redisIdWorker.nextId("order");
    //    voucherOrder.setId(orderId);
    //    //2.4用户id
    //    voucherOrder.setUserId(userId);
    //    //2.5代金卷id
    //    voucherOrder.setVoucherId(voucherId);
    //    //创建阻塞队列
    //    orderTasks.add(voucherOrder);
    //    //获取代理对象
    //    proxy = (IVoucherOrderService) AopContext.currentProxy();
    //    return Result.ok(orderId);
    //}
    
    private void handleVoucherOrder(VoucherOrder voucherOrder) throws InterruptedException {
        //获取用户
        Long usersId = voucherOrder.getUserId();
        //获取锁(可重入)，指定锁的名称
        RLock lock = redissonClient.getLock("lock:order:" + usersId);
        //SimpleRedisLock lock = new SimpleRedisLock("order:" + usersId, stringRedisTemplate);
        boolean isLock = lock.tryLock(1L, TimeUnit.SECONDS);
        if (!isLock){
            //获取锁失败
            log.error("不允许重复下单");
            return ;
        }
        try {
            //获取代理对象（事务）
            //IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            proxy.createVoucherOrder(voucherOrder);
        }finally {
            lock.unlock();
        }
    }
    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //一人一单判断
        //查询订单、判断订单是否存在
        Long usersId = voucherOrder.getUserId();


        Integer count = query().eq("user_id", usersId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        if (count>0){
            //用户已经购买过了
            log.error("用户已经购买过了");
            return;
        }

        //5.扣减库存
        boolean success = seckillVoucherService
                .update()
                .setSql("stock = stock - 1") //set stock = stock - 1
                .eq("voucher_id", voucherOrder.getVoucherId()) //where id = ? and stock > 0
                .gt("stock",0)
                .update();
        if (!success){
            //扣减失败
            log.error("扣减失败");
            return;
        }

        save(voucherOrder);

    }
    //@Override
    //public Result seckillVoucher(Long voucherId) throws InterruptedException {
    //    //1.查询优惠劵
    //    if (voucherId==null){
    //        return Result.fail("优惠卷id为空，请检查！");
    //    }
    //    Voucher voucher = voucherService.getById(voucherId);
    //    if (voucher==null){
    //        return Result.fail("优惠劵不存在");
    //    }
    //    //2.判断秒杀是否开始
    //    SeckillVoucher seckillVoucher = seckillVoucherService.getById(voucherId);
    //    if (seckillVoucher.getBeginTime().isAfter(LocalDateTime.now())){
    //        return Result.fail("秒杀未开始");
    //    }
    //    //3.判断秒杀是否已经结束
    //    if (seckillVoucher.getEndTime().isBefore(LocalDateTime.now())){
    //        return Result.fail("秒杀已结束");
    //    }
    //    //4.判断库存是否充足
    //    if (seckillVoucher.getStock()<1) {
    //        return Result.fail("库存不足");
    //    }
    //    Long usersId = UserHolder.getUser().getId();
    //    //获取锁(可重入)，指定锁的名称
    //    RLock lock = redissonClient.getLock("lock:order:" + usersId);
    //    //SimpleRedisLock lock = new SimpleRedisLock("order:" + usersId, stringRedisTemplate);
    //    boolean isLock = lock.tryLock(1L, TimeUnit.SECONDS);
    //    if (!isLock){
    //        //获取锁失败
    //        return Result.fail("不允许重复下单");
    //    }
    //    try {
    //        //获取代理对象（事务）
    //        IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
    //        return proxy.createVoucherOrder(voucherId);
    //    }finally {
    //        lock.unlock();
    //    }
    //}

    //@Transactional
    //public Result createVoucherOrder(Long voucherId) {
    //    //一人一单判断
    //    //查询订单、判断订单是否存在
    //    Long usersId = UserHolder.getUser().getId();
    //
    //
    //        Integer count = query().eq("user_id", usersId).eq("voucher_id", voucherId).count();
    //        if (count>0){
    //            //用户已经购买过了
    //            return Result.fail("用户已经购买过一次了！");
    //        }
    //
    //        //5.扣减库存
    //        boolean success = seckillVoucherService
    //                .update()
    //                .setSql("stock = stock - 1") //set stock = stock - 1
    //                .eq("voucher_id", voucherId) //where id = ? and stock > 0
    //                .gt("stock",0)
    //                .update();
    //        if (!success){
    //            //扣减失败
    //            return Result.fail("库存扣减失败");
    //        }
    //
    //
    //        //6.创建订单
    //        VoucherOrder voucherOrder = new VoucherOrder();
    //        //订单id
    //        long orderId = redisIdWorker.nextId("order");
    //        voucherOrder.setId(orderId);
    //        //用户id
    //        Long userId = UserHolder.getUser().getId();
    //        voucherOrder.setUserId(userId);
    //        //代金卷id
    //        voucherOrder.setVoucherId(voucherId);
    //        save(voucherOrder);
    //        //7.返回订单id
    //        return Result.ok(orderId);
    //
    //}

}
